/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.sql;

import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rex.RexCall;
import org.apache.calcite.rex.RexVisitor;
import org.apache.calcite.sql.type.SqlOperandTypeChecker;
import org.apache.calcite.sql.type.SqlOperandTypeInference;
import org.apache.calcite.sql.type.SqlReturnTypeInference;
import org.apache.calcite.sql.type.SqlTypeUtil;
import org.apache.calcite.sql.validate.SqlMonotonicity;
import org.apache.calcite.sql.validate.SqlValidator;
import org.apache.calcite.util.Litmus;
import org.apache.calcite.util.Util;

/**
 * A unary operator.
 */
public class SqlNotOperator extends SqlOperator {
  //~ Constructors -----------------------------------------------------------

  public SqlNotOperator(
          String name,
          SqlKind kind,
          int prec,
          SqlReturnTypeInference returnTypeInference,
          SqlOperandTypeInference operandTypeInference,
          SqlOperandTypeChecker operandTypeChecker) {
    super(
            name,
            kind,
            leftPrec(prec, true),
            rightPrec(prec, true),
            returnTypeInference,
            operandTypeInference,
            operandTypeChecker);
  }

  //~ Methods ----------------------------------------------------------------

  public SqlSyntax getSyntax() {
    return SqlSyntax.PREFIX;
  }

  public String getSignatureTemplate(final int operandsCount) {
    Util.discard(operandsCount);
    return "{0}{1}";
  }

  protected RelDataType adjustType(
          SqlValidator validator,
          SqlCall call,
          RelDataType type) {
    if (SqlTypeUtil.inCharFamily(type)) {
      // Determine coercibility and resulting collation name of
      // unary operator if needed.
      RelDataType operandType =
              validator.getValidatedNodeType(call.operand(0));
      if (null == operandType) {
        throw new AssertionError("operand's type should have been derived");
      }
      if (SqlTypeUtil.inCharFamily(operandType)) {
        SqlCollation collation = operandType.getCollation();
        assert null != collation
                : "An implicit or explicit collation should have been set";
        type =
                validator.getTypeFactory()
                        .createTypeWithCharsetAndCollation(
                                type,
                                type.getCharset(),
                                new SqlCollation(
                                        type.getCharset(),
                                        collation.getCollationName(),
                                        collation.getCoercibility()));
      }
    }
    return type;
  }

  @Override public SqlMonotonicity getMonotonicity(SqlOperatorBinding call) {
    if (getName().equals("-")) {
      return call.getOperandMonotonicity(0).reverse();
    }

    return super.getMonotonicity(call);
  }

  @Override public boolean validRexOperands(int count, Litmus litmus) {
    if (count != 1) {
      return litmus.fail("wrong operand count {} for {}", count, this);
    }
    return litmus.succeed();
  }

  public void accept(RexVisitor visitor, RexCall call) {
    visitor.visit(this, call);
  }
}

// End SqlPrefixOperator.java
